Bag bottomer



July 10, 1956 Filed March 9, 1955 E. E. BURROUGHS BAG BOTTOMER 7Sheets-Sheet 1 INVENTOR.

July 10, 1956 E. E. BURROUGHS BAG BOTTOMER 7 Sheets-Sheet 3 Filed March9, 1955 E BUREOUGHS- ATTORNEY-5.

July 10, 1956 E. E. BURROUGHS BAG BOTTOMER 7 Sheets-Sheet 4 Filed March9, 1955 INVENTOR. E 0 WINE BUEROUGHS.

BY w d L W,

ATTOR/VEKS.

July 10, 1956 E. E. BURROUGHS BAG BOTTOMER 7 Sheets-Sheet 5 Filed March9, 1955 i: 11 V IN VEN TOR. EDWIN E BUEIPOUGH-S.

I ATTORNEYS.

BAG BOTTOMER 7 Sheets-Sheet 6 July 10, 1956 E. E. BURROUGHS Filed March9, 1955 July 10, 1956 BURRQUGHS 2,753,769

BAG BOTTOMER Filed March 9, 1955 7 Sheets-Sheet 7 I N V EN TOR.

51: W/NEBUEEOUGHS.

M i 1+, un

' ATTOIFWEVJ:

United States Patent BAG BOTTOMER Edwin E. Burroughs, Pensacola, Fla.,assiguor to St.

Regis Paper Company, New York, N. Y., a corporation of New YorkApplication March 9, 1955, Serial No. 493,135

Claims. (Cl. 93-22) This invention relates to improvements in bag bottomforming apparatus, and more particularly to apparatus for insuringfolding over of the side flaps of a spread apart bag tube end accuratelyalong selected lines.

In the formation of pasted bag bottoms by means of high speed machineswhich pull the individual bag tubes in succession sideways through a bagbottomer, and which operate upon the opposite extremities thereof toform the bottoms, some difiiculty has been experienced with respect tothe accurate folding of the bottoms and thus with respect to accuratepositioning of preformed sleeves which are to form the valve sleeves ofthe valved bag bottoms. Such a sleeve has a tendency to become slightlyout of alignment or canted after it has been applied at high speed tothe rapidly advancing partial-1y formed bag bottom. In bag bottomers ofthe aforementioned general type where the side fiaps are folded over toform the bag bottoms by means of foldover shoes past which the bagbottoms are pulled, there is a tendency for the trailing portion of thebag bottom to be slightly spread apart beyond its normal and desireddimension after such =foldover, and thus to be somewhat broader than theleading portion of the bag bottom. It has been found desirable, but notnecessarily mandatory, in this type of bottomer to insert such sleeve ata trailing corner of the bag tube end, and because of the tendency ofthe trailing region of the bag bottom so to spread apart somewhatexcessively as aforementioned, there is increased a tendency for thesleeve to become canted or slightly out of alignment.

One of the objects of the present invention is to overcome thedifficulties aforementioned or to reduce same to negligible proportions.

Another object is to provide novel means for high speed bottoming of bagtubes whereby the finally bottomed bag tubes are provided with bottomswhich are neither too narrow nor too wide but which are of a selectedand uniform width.

A further object is to provide an apparatus of this general characterwhich is capable of high speed use and thus well adapted for massproduction.

Another object is to provide apparatus of this character which is ofwide versatility because of its ability to accommodate a wide variety ofbag bottom sizes and wherein adjustment of the apparatus to accommodatea new bag bottom size can be effected with substantially negligible downtime or period of inoperation of the machine.

The invention, in one aspect thereof, is constituted by a bag bottomforming apparatus having a bag tube conveyor including grippers forconsecutively gripping each of a plurality of bag tubes on the leadingedge thereof and pulling same in succession along a common path throughsaid apparatus in spaced relationship. Grippers for successive tubes areseparated by a selected interval. The apparatus includes mechanism forspreading a tube end of each of such tubes moved by the conveyor andforming thereupon two side flaps, two end flaps, and two parallel bottomfold score lines. In combination with the above, there is employedsupplementary conveyor means for conveying in succession a plurality ofpairs of end fiap press elements in the same direction and at the samespeed as the aforementioned bag tube conveyor. The press elements of agiven pair are spaced at a distance substantially equal to the length ofa bottom fold score line and corresponding press elements of any twosuccessive pairs thereof are spaced at the aforementioned selectedinterval which separates said successive grippers. The supplementaryconveyor means and the press elements moved thereby are constructed andarranged for successively pressing the end fiaps of each of the oncomingbags. Each end flap is pressed at the corresponding opposite termini ofthe two opposite bottom fold score lines thereon, said termini alsodefining the termini of a bottom width line Which is perpendicular toand between such score lines. Side flap folding means are also employedand are positioned for acting contemporaneously with such pressing ofthe end flaps by said press elements whereby all of the bag bottoms areformed at a precise and uniform width. If desired, and just prior to thepressing of the end flaps, a preformed valve sleeve can be depositedupon one of the end flaps of each tube in a desired position which willbe maintained by its respective press element.

Various, further and more specific objects, features and advantages ofthe invention will clearly appear from the detailed description givenbelow taken in connection with the accompanying drawings which form apart of this specification and illustrate, by way of example, preferredarrangements of apparatus for carrying out the invention. The inventionconsists of such novel combinations of features as may be shown anddescribed in connection with the equipment herein disclosed.

In the drawings:

Fig. 1 is a perspective view of a schematic nature illustratingapparatus embodying one form of the invention;

Figs. 2a to 2k, inclusive, illustrative steps in the formation of apasted bag bottom by means of the apparatus shown in Fig. 1;

Fig. 3 is a plan view on a relatively enlarged scale, as compared toFig. 2, of a single end flap press element shown in pressing relationupon the end flap of a bag bottom;

Fig. 4 is a side elevation of a portion of the apparatus embodying thepresent invention;

Fig. 5 is an end view of the apparatus shown in Fig. 4;

Fig. 6 is a top plan view of the apparatus shown in Fig. 4;

Fig. 7 is a view of the righthand portion of the apparatus shown in Fig.4 but illustrating certain details thereof which are omitted from thelatter figure, Fig. 7 also illustrating certain conveyor means forremoving the bottomed bag tubes from the bag bottonier;

Fig. 8 is a side elevation of a schematic nature illustrating means foreffecting a final bag bottom pressing;

Fig. 8a is a front view of a main roller employed in the apparatus ofFig. 8;

Fig. 9 is a sectional view taken substantially along line 9-9 of Fig. 4;

Fig. 10 is a sectional view taken substantially along line Iii-10 ofFig. 4; and

Fig. 11 is a sectional view taken substantially along line 1111 of Fig.7.

Referring now to the drawings, with particular reference to Fig. l, thepresent invention includes travel- 3 ing end flap press means 26 whichact in combination with and form a part of a bag bottomer machine 21,the end flap press means operating principally during the side flapfoldover period, that is, during the time that the side flaps of thespread bag tube end are being folded over to form the bag bottom.

A bag tube such as 22, which is .one of a succession of bag tubes, ispulled in the direction of the arrow 23 by means of clamps 24 and 25which are secured in the usual fashion to a pair of endless sprocketchains as and 27, respectively.

Such bag tubes are automatically fed to the apparatus preferably bymeans of an automatic feeder 23 which in sorts the bags in timedrelationship into the grippers, such as 24- and 25, whereby the tubesare pulled sideways through the machine.

Each of the bag tubes is acted upon by the bag boa tomer, that is, bythe several units of the bag bottomer to form the bag bottoms onopposite extremities of the tube as shown in Figs. 2a to 21', inclusive.

In the latter figure, namely Fig. 21', the sleeve is plied at thetrailing corner .of one extremity of the partially formed bag bottomalthough, of course, it is not mandatory to apply such a sleeve.

During the formation .of the bottom, as shown in Figs. 2a to 21', aswill be more fully explained hereinbeiow, a pair of parallel bottom foldscore lines 2-9 and 38 (Fig. 2e) are formed which are preferablyequidistant from a main or primary center score line 31. The parallelbottom fold score lines 29 and 3%) are those about which side flaps 32and 33 are to be folded over to form the bottom.

After the bottom has been spread open and such side flaps have beenpartially folded, for example, as shown in Fig. 2h (the latter foldingnot being essential to the invention), a pair of traveling press orhold-down elements 34, 35, as shown in Fig. 2 are pressed transverselydown upon end flaps 35 and 37 of, for example, the lefthand bag tubeend, as viewed from the automatic feeder 23, it being understood, ofcourse, that similar hoid-down elements may be pressed against theopposite end flaps at the opposite end of the tube. Press elements .34,55 :are generally of bar-like configuration having pressing faces to bedescribed more fully herebelow.

Referring again to Fig. 2e and also to Fig. 3, it will be noted at .theleftha-nd extremity of the bottom fold score lines 29, 30., there existsan imaginary line or meridian designated by the numeral 4t) whichcomprises a bottom width line. This line exists between the left-handterminal points 2% and 39a of the bottom fold score lines 29 and 36).

Similarly a righthand bottom width line 41 (Fig. 2c) is formed betweenthe terminal points 29b and 3% at the righthand extremities of thebottom fold score lines 2% and 30.

In order to achieve the object of the present invention, the hold-downor press bars should press down upon the end flaps 36 and 37 in theregions immediately adjacent the extremities of the lines and 41.. Thatis, the hold-down bars do not necessarily have to press directly alongthe lines 46 and 4-1 but should press the end flaps in the regions ofthe extremities of such lines thereby to facilitate and make moreaccurate the folding over of the side flaps 32 and 33.

Suitable novel conveyor means are provided for mounting the hold-downbars 34 and 35 aforementioned, which means will be described more fullyhereinafter.

Accordingly, each extremity of the bag tube is pressed downwardly, asshown in Figs. 2 and 2k, during the foldover of the side flaps, andthereafter the bag tube is, of course, directed out from under the pressbars and the bag bottom is pressed by suitable means, for ex ample, asshown in Pig. 8. Such'means are generally designated at 42 in suchfigure.

The general operation of the apparatus has been ded scribed above. Nowagain reverting to Figs. 1, 2 and 3, there will be further describedadditional details of the bag bottoming machine.

After a bag tube, such as 22, has been fed from the automatic feeder 2%into the grip of a pair of cooperating grippers 24, 25 of the main bagtube conveyor 26, 27, the tube is passed beneath a pair of slitters 43,24 which are positionedover the opposite extremities thereof and whichform the slits 4-5 comprising one pair of slits on each extremity, asshown in Fig. 2a.

Thereafter the following takes place in succession:

Main or center score lines 46 are formed, as shoen in Fig. 2b., by thecenter or main scorers 47 (Fig. l);

The opposite extremities of the bag tube are bent (Fig. 20) by the endbender units 48.;

The tube ends thereafter are preliminarily opened by preliminary openerunits 49; thereafter such ends are spread and the side and end flapsformed by the spreader units 50 following which the now spread andpartially formed bag bottom is pressed by presser units 51.; the effectof such preliminary opening, spreading and pressing being illustrated inFig. 2d;

Thereafter the aforementioned bottom fold score lines 2) and 34) (Fig.2e) are formed at each extremity of the bag tube by means of the bottomfoid score line :units 52 whereby the imaginary bottom width lines asand can be visualized in the same figure;

Thereafter adhesive or paste is applied to selected areas of the nowspread tube ends by means of pastor units 53, the position of such pasteareas being indicated in Fig. 2f;

Thereafter the side flaps 32 and 33 are bent upwardly through 90, asillustrated in Figs. 2g and 211, by means of side flap bender unit 54;

Following this a sleeve applicator 55 deposits a sleeve 55a in one ofthe corners of the tube end, as illustrated in Fig. 2-1, preferably inone of the trailing corners, and in the form shown in the 'lefthandtrailing corner, as viewed from the feeder 28;

Thereafter the aforementioned end flap press means 25 engages the tubeend for pressing downwardly upon the opposite cndflaps an, 37, as shownin Fig. 2], the pressing occurring by the action of the aforementionedpress bars 34, 35 which are urged toward an endless belt 56therebeneath, there being one such belt on each side of the bottomer, itbeing understood that the tube end is inter posed between such end flappress elements 34, and the respective end-less belt. As is best shown inFig. 6, a side flap foldover unit '57 is situated beneath each of thepress units 29 for the purpose of folding first one of the side flapsover into the plane of the bag bottom and thereafter the other side flapover the first one thereby to form the bag bottom as shown in Fig. 2k,this occurring during the operation or pressing action of the press bars34 and 55. The force of gravity urges the chains and press bars securedthereto down upon the bag tube ends resting upon the belts '56. A firmsupport may be positioned beneath each belt 56 to prevent it fromsagging.

Thereafter the now folded bag bottom is directed onto further bagconveyor means '58 (Fig. l) which has associated therewith theaforementioned bag bottom pressing means 4-2 which effects the finalpressing of the bag bottom and delivers the completed bags through anoutlet 58a.

In my U. S. Patent 2,579,047, granted October 2, l, and in my copendi-ngapplication Serial No. 422,575, there are shown bag bottom forminguni-ts which may be similar to the following units herein mentioned: 43,47, as, 49, 5t 51,, 52, '53 and '55.

Referring now to lFi-g. 3, it will be seen that the width of the bagbottom is determined by the dimension between the points 29a: and 3%,the line 4%) therebetween, as aforementioned, being designated thebottom width line, there being an analogous line at the oppositeextremity of the same bag bottom. in normal commercial practice, thevariation in the widths of bag bottoms illustratively is presentlybetween about 2 /2 inches up to about 5 /2 inches, although, of course,these are not necessarily fixed limits. Consequently, it is desirable tohave press or hold-down bars which are capable of accommodating anywidth of bag bottom, within reasonable limits, and which bars can beeasily adjusted in position with minimum effort and time. The bars 34and 35 are adjustable as to the distance therebetween in a novel andrapid manner, as will more fully appear hereinafter, not only in orderto accommodate bag tubes of differing widths, but also to accommodatebag bottoms of differing widths. In order to accommodate such varyingwidths of bag bot toms, each of the bars, such as 34, as is well shownin Fig. 3 is provided with a protuberance, for example, 34a havingpreferably a fiat bottom face for pressing down upon the end flap andwhich is in the shape of an isosceles trapezoid as formed between thepoints 59, 60, 61 and 62. The dimension between the points 59 and 62preferably is somewhat greater than maximum bottom width which is to beaccommodated, and accordingly the dimension between the points 60 and 61is somewhat less than the smallest bottom width to be accommodated. Itwill be seen from the top plan view of the isosceles trapezoid 34a ofFig. 3 that it is provided with the edges 63 and 64 which respectivelyare between the points 59, 60 and 61, 62. Such edges 63 and 64 comprisethe non-parallel and equal sides of such quadrilateral and thus are ableto press satisfactorily downwardly upon the region of the termini of thebottom width line 40- or alternatively, to press down in the region ofthe termini 29a, 30a of the bottom fold score lines 29 and 30 providingthe length of such line is within the selected limits. It is notentirely necessary for the press bars to press downwardly over asubstantial area in the region intermediate such termini but it has beenfound to be desirable and, of course, the pressing down of such barsupon diagonal fold lines 65 and 66 over at least a portion of the lengththereof has a beneficial effect in the pressing of the end flap butagain is not absolutely necessary in view of the prior pressing of suchdiagonal fold lines by means of the presser units 51.

Referring now to Figs. 1 and 4, there will be described one of theaforementioned units 20 which embraces several pairs of press bars andalso the conveyor means therefor. Such conveyor means are of the endlessband type, each such band comprising, in the form shown, a sprocketchain.

In order to permit easy adjustment of the dimension between the twopress bars comprising any pair thereof, such as bars 34 and 35 (Fig.2f), I have found it desirable to secure the opposite extremities of oneof the bars 34 to appropriate opposite points of a first pair of spacedendless conveyor chains 67, 68 (Fig. 1) and to secure the oppositeextremities of the other hold-down or press bar 35 to appropriateopposite points of another pair of endless conveyor chains disposedbetween the first pair, such second pair being designated 69 and 70(Figs. 1 and 2 Thus it is possible to adjust the aforementioneddimension between the bars 34 and 35 by, for example, loosening a hubclamp for one of the pairs of chains, e. g. 69, 70 and shifting same tothe desired adjusted position. It is, of course, understood that theendless conveyor chains 67, 68 and 69, 70 pass over suitable sprocketwheels in a manner to appear more fully hereinafter.

Further although only one of the press units 20 is fully describedherein, it is understood that the opposite unit is analogous thereto.

There are secured to the outermost pair of chains 67, 68 four long pressbars each of which is somewhat longer than each of a correspondingnumber of short press bars which are secured to the innermost pair ofendless conveyor chains 69, 70. I have found it'desirable to secure fourof such bars to each of such pairs of chains although it is, of course,possible to employ a difierent number, it being understood that the samenumber of press bars for the first pair of chains is employed upon thesecond pair.

In the form shown in the drawings, the four long press bars secured tothe chain pair 67, 68 are designated 34, 34a, 34b and 340. These longbars cooperate respectively with the following short press bars 35, 35a,35b and 35c which, as aforementioned, are secured to the inner pair ofendless chains 69, 70.

Referring now to Figs. 1, 4, 5 and 6, further details of the press unit20 will now be described, together with the relationship thereof to themain bag tube conveyor 26, 27. The latter two elements 26 and 27preferably comprise sprocket chains which respectively pass oversprocket wheels 26a, 26b and 27a, 27b (Fig. 1). There, of course, areprovided suitable guide rails or supports beneath each of the upper runsof the endless sprocket chains 26, 27 for supporting same as they passthrough the machine. Such rails, together with analogous rails situatedabove the lower runs of such chains, will be described below inconnection with Fig. 9.

Referring again to Figs. 4, 5 and 6, each of the chains 67-70,inclusive, passes over suitable sprocket wheels. For example, theinnermost chain 67 at its lefthand extremity (Fig. 6) passes over thesingle relatively large sprocket wheel 71 and, at the righthandextremity or outlet extremity thereof, passes over a pair of superposedsprocket wheels 72 and 73 which are respectively mounted upon an uppershaft 74 and a lower shaft 75, such shafts being mounted in suitablebearings and having respectively secured thereto driving gears I6 and 77via which power is communicated from a main drive to be explained below.

Analogously, the opposite chain 68 of the pair 67, 68 passes at one endover' a relatively large sprocket wheel 78 (Fig. 6) and at the other enda pair of smaller superposed sprocket wheels 79 and 80 which arerespectively mounted upon said shafts 74 and 75.

The endless sprocket chain 69 in turn is mounted at one end upon asingle relatively large sprocket wheel 81 and at the other end upon twosmaller sprocket wheels 82 and 83 respectively mounted on such shafts 74and 75. Likewise the other conveyor chain 70 of this pair (69, 70) ismounted upon large sprocket wheel 84 at the lefthand extremity thereofand at the other extremity upon the sprocket wheels 85 and 86 alsorespectively mounted on the shafts 74 and 75.

The advantage of the particular type of mounting of such chains 67-70,inclusive, is to facilitate the adjustment of the dimension between anytwo cooperating press bars, such as 34 and 35. This can be effected asfollows:

The gears 76 and 77 are secured to their respective 'shaftsby clamp hubs76a and 77a and thus in order to disconnect either one of them it is asimple matter to loosen the respective clamp. Each of the relativelylarge sprocket wheels 71, 78 and 81, 84 rotate freely upon theirrespective shafts. However, this is not so of all of such smallersprocket wheels, such as 72, 73. That is, the pair of sprocket wheels82, 85 are freely rotatable upon the shaft 74 whereas the coaxialsprocket wheels 72 and 79 are keyed to such shaft and thus rotatetherewith. The converse situation is true with respect to the shaftwherein the sprocket wheels 33, 86 are keyed to such shaft 75 whereasthe relatively small sprocket wheels 73, rotate freely thereupon. Thisconstruction thus permits, by loosening, for example, the clamp hub 76a,the shifting of the outermost pairs of chains, namely, 67, 68, withrespect to the relatively stationary chains 69, 70. And conversely, ifit is desired to make the adjustment by means of the hub 77a, the lattermay be loosened and consequently the innermost pair of chains 69, 70 canbe shifted and the press bars thereupon can be shifted therewith.Thereafter, of course, the pertinent 7 clamp hub is tightened when thedesired adjustment has been made.

Power is communicated to the various conveyor chains 26, 27 and 67-749,inclusive, by the following gear trains: A gear 87 in the lower middleportion of Fig. 4 is driven by suitable power means (not shown) andcommunicates power to the aforementioned gears 76, 77 (Fig. via twoidler gears 83, 8.9, the latter meshing with a gear 9b which in turnmeshes with :a gear M, the latter communicating torque to a gear '92 onthe shaft 93 on which is a further gear 94 which in turn meshes withboth of the aforementioned gears 76 and 77.

The righthaud endless belt 56, as shown in Fig. 1, is well illustratedin Fig. 7 for passing beneath the region over which moves the severalpress bars. Cooperating with such rightha-nd endless belt 56 and movingthercwith at the same speed are the righthand press bars 34, 35 and 34a,35a, and so on.

Brcferring to Fig. 5, Ihave found it desirable to be able to adiust theside flap bend-up device to accommodate bag bottoms of widths having adimension within the range of a small dimension 95 and a large one 96.Consequently, it is desirable to be able to adjust, with respect to thebag botto 3. center line, the side flap bend-up devices and to this endsuitable manually adjustable side flap bend-up means, as shown forexample at 97, can be employed and which can be clamped into position bymeans of suitable hand clamps, one of which is shown, for example, at98.

The distance of the side flap foldover shoe 57, which embraces twoseparate shoes 57a and 571), above the endless belt 56, can be adjustedby means of manually controlled knobs 99 and 1th (Fig. 4).

Referring to Fig. 7, a guide belt 101 passing over rollers i 52 and 1 33may be provided interposed between the righthand extreme region of thetwo opposite endless belts 56, reference being bad to Fig. 6 to indicatesuch position. Such belt 191 guides the bottomed bag tubes onto the eXitor outlet belt means 5% (Fig. l and Fig. 7) which consists of thefollowing belt system:

A main exit belt 1-134 which over the initial portion thereof cooperateswith a superposed belt 195 for directing the bottomed bag tubes into theaforementioned bottom pressing means 42. The belt 1%, for the pressingoperation, passes over a relatively large roller lilo over a portion ofthe periphery of which, preferably about l8t,-, there is pressed asecond belt 197 mounted as shown in Fig. 8.

Referring now to Fig. 9, the elements for bending upwardly andthereafter holding the side flaps in their upwardly bent condition arewell illustrated at 108 and 166*, such elements comprising parts of theaforementioned side flap bender unit .54. Elements 3&8, 169 are mountedrespectively upon axially shi'ftable shafts 110 and lift which areclamped, respectively by means of said clamping device 98 aforementionedand also 112, in desired positions, it being, of course, understood thatthey can be moved toward or away from one another as desired by suitableadjustment of such clamping means 3'8 and 112.

Also well shown in Fig. 9 are chain guide rails 113 and lid forsupporting the upper runs of the outermost conveyor chains 67, 68 andfurther there are shown chain rails E and I116 for supporting the upperrun of the inner pair of chains 69, 70.

Analogously there are provided chain rails 117 and 113 for guiding thelower runs of the chains 6'7, 66, respectively, and the rails T119 and126 for the lower runs of the innermost pair of chains 69, 7respectively.

Referring again to Figs. 1 and 4, the interval between any twosuccessive grippers on the main bag tube conveyor 26, 27, such twosuccessive grippers being shown at 24 and 24a, must be the same as theinterval between the press bars 34-, 34a, of Fig. 4. Bars 34 and 34::comrise corresponding bars of two successive pairs thereof.

By virtue of this relationship of intervals, the press bars are broughtinto proper phase relationship with the encoming bag tubes and, ofcourse, are moved therewith at the same speed. That is, the speed of theconveyor chains which move the press bars is equal to the speed of themain bag tube conveyor 26, 27 and also to the endless belts 56.

What is claimed is:

l. In an automatic bag bottom forming apparatus havlug a bag tubeconveyor, including spaced gripping means for consecutively grippingeach of a plurality of bag tubes on the leading edge thereof and pullingsame in succession relative to said apparatus in spaced relationshipseparated by a selected interval, mechanism for consecutively spreadinga tube end of each of such tubes moved by said conveyor and formingthereupon two side flaps, two end flaps, and two parallel bottom foldscore lines, the combination therewith of a plurality of pairs of endflap press elements, supplementary conveyor means for conveying insuccession such plurality of pairs of press elements in the samedirection and at the same speed as the aforementioned conveyor, thepress eleen-ts of a given pair being spaced at a distance substantiallyequal to the length of a bottom fold score line, supporting means forsaid ends situated adjacent the path of said press elements forproviding a backing against which portions of such end flaps can bepressed, said supplemen tary convey-or means and press elements beingconstructed and arranged whereby said elements successively press theend fiaps of each of the oncoming bags in the region of correspondingopposite termini of .two opposite bottom fold score lines, correspondingpress elements of any two successive pairs thereof also being separatedby the same aforementioned selected interval.

2. In an automatic bag bottom forming apparatus having a bag tubeconveyor, including spaced gripping means for consecutively gripping aplurality of bag tubes each on the leading edge thereof and pulling samein successi-on relative to said apparatus in selected spacedrelationship, mechanism for spreading the tube end of each of the tubesmoved by said conveyor and forming there upon two side flaps, two endflaps, two bottom fold score lines, and two opposite bottom width lines,mechanism for applying adhesive consecutively to the spread tube cardsupon selected areas thereof, the combination therewith of a plurality ofend flap press elements, supplementary conveyor means for conveying insuccession such press elements in the same direction and at the samespeed as the aforementioned bag tube conveyor, such press elements ofany given pair thereof for acting upon the two end flaps of a given bagtube being spaced. at a distance substantially equal to the distancebetween two such opposite bottom width lines, said conveyor means andpress elements being constructed and arranged where by each of saidelements press downwardly upon its respective end flap in the region ofthe termini of a bottom width line.

3. In apparatus of the class described for automatically forming bagbottoms upon bag tubes, such apparatus having a bag tube conveyorincluding means for gripping a plurality of tubes on the leading edgesthereof and pulling same transversely thereof through such apparatusthereby moving same in spaced relation and in succession relative to bagbottom forming units of such apparatus, such units including means foropening and spreading along a tube end center line at least one end ofeach oncoming bag tube thereby to form upon each a pair of end flapseach having a pair of diagonal fold lines, and also to form a pair ofside flaps, means for forming on such spread tube end a pair of parallelbottom fold score lines parallel to the direction of motion of said bagtubes and substantially equally spaced from such center line, saidparallel bottom fold score lines each terminating at each end thereofintermediate the extremities of its respective diagonal fold line, theterminal points of the parallel bottom fold score lines upon a commonend flap being located along a line which is substantially perpendicularto the path of movement of the bag tubes thereby forming an end flapbottom width line for each of said end flaps, characterized by aplurality of pairs of end flap press elements, conveyor means for movingin succession such press elements, the latter extending transversely ofeach of the oncoming end flaps of each oncoming bag tube, the presselements of each pair thereof for acting on a given tube end beingspaced upon such conveyor means at a dimension substantially equal tothe distance between the opposite termini of the bottom fold score linesof such tube end, each such element being constructed and arranged forpressing each end flap substantially at the two terminal points of thebottom width line of such end flap, and side flap fold means for actingconsecutively upon the tubes during such pressing by said press elementswhereby one of said side flaps is first folded along its respectivebottom fold score line and thereafter the other side flap is folded overthe first one also along its respective bottom fold score line.

4. ln apparatus for automatically forming bag bottoms upon bag tubes,such apparatus having a bag tube conveyor including means for gripping aplurality of tubes each at the leading edge thereof and pulling samethrough such apparatus thereby moving same in spaced relation insuccession relative to the bag bottom forming units of such apparatus,such units including means for opening and spreading at least one end ofeach oncoming bag tube thereby to form a pair of end flaps and a pair ofside flaps thereupon, means for forming on each such spread tube end apair of parallel bottom fold score lines parallel to the direction ofmotion of said bag tubes and equally spaced from the center line of thespread tube end, the terminal points of the parallel bottom fold scorelines upon a common end flap being along a line which is perpendicularto the path of movement of the bag tubes thereby forming an end flapbottom width line for each of said end flaps, characterized by aplurality of end flap press elements, conveyor means for moving insuccession such plurality of press elements, the latter extendingtransversely of each of the oncoming end flaps of each oncoming bagtube, such press elements for acting on the two end flaps of a giventube end being spaced upon such conveyor means at a dimensionsubstantially equal to the distance between opposite bottom width linesof a bag bottomer, a supporting surface for supporting one side of suchtube ends during the pressing thereof by such press elements acting onthe other side thereof, such press elements being constructed andarranged for pressing each end flap substantially at the two terminalpoints of the bottom fold score lines on such end flap.

5. In an automatic bag bottom forming apparatus, the combinationcomprising a bag tube conveyor, means for opening and spreading an endof each bag tube conveyed by said conveyor, such opening and spreadingmeans forming upon each such spread bag tube end: two opposite sideflaps and two opposite end flaps, such opening and spreading meansthereby preliminarily forming the bag bottom and spreading the tube endwith respect to a center line parallel to the direction of motion of thebag tubes as moved by said conveyor, such center line intersecting theforward and trailing end flaps at such end of the bag tube, at leastaportion of each of said end flaps being substantially triangular inconfiguration by virtue of diagonal fold lines formed thereupon inresponse to said bag tube spreading, means for forming a pair ofparallel bottom fold score lines upon each such spread tube end onopposite sides of said center line and parallel thereto, each bottomfold score line terminating at the opposite extremities thereof alongthe respective opposite diagonal fold lines situated on the same side ofsaid center line, said parallel bottom fold score lines extending in thedirection of motion of the bag tubes as moved by said bag tube conveyor,the leading extremities" of such a pair of said bottom fold score linesbeing positioned along a line which is perpendicular to the path ofmovement of the bag tubes and which defines therebetwecn the limits of abottom width line, the same being true of the trailing extremities ofsuch bag fold score lines, such bottom width lines thus being parallel,a plurality of end flap press elements, subsidiary con veyor means formounting said elements in spaced relation thereon and for moving same insuccession along the path of movement of such tube ends, such elementsbeing at least two in number, the elements of each pair thereof beingseparated by a distance substantially equal to the dimension between theaforementioned parallel bottom width lines which extend transversely ofthe leading and trailing end flaps of a bag tube, such subsidiaryconveyor means and said bag tube conveyor being operatively associatedfor movement at a common speed whereby each pair of such press elementscan move at the same speed along with each bag tube end, tube endsupport means, each such press element being constructed and arrangedfor coacting with such support means for pressing each end fiap of eachspread bag tube end in the immediate region of opposite terminal pointsof its respective bottom width line, and side flap fold means for actingupon the side flaps of a tube end for folding one side flap of the tubeend over the other side flap thereof while said end flap press elementsare pressing the opposite end flaps thereof.

6. In an automatic bag bottom forming apparatus, the combinationcomprising, a bag tube conveyor, mechanism for opening and spreading anend of each bag tube conveyed by said conveyor, such opening andspreading mechanism forming upon each such spread bag tube end sideflaps and end flaps, said tube end opening and spreading mechanismthereby preliminarily forming the bag bottom and spreading the tube endwith respect to a center line parallel to the direction of motion of thebag tubes as moved by said conveyor means, such center line intersectingthe forward and trailing end flaps at such end of such bag tube end,means for forming a pair of parallel bottom fold score lines on oppositesides of said center line and parallel thereto, each bottom fold scoreline terminating at opposite ends thereof at and end flap, said parallelbottom fold score lines extending in the direction of motion of the bagtubes as moved by said bag tube conveyor, a plurality of end flap presselements, subsidiary conveyor means mounting said elements in spacedrelation and for moving same in succession along the path of movement ofsuch tube ends, such press elements being at least two in number, theelements of each pair thereof for acting on a tube end being separatedby a distance substantially equal to the length of such bottom foldscore line, such subsidiary conveyor means and said bag tube conveyorbeing operatively associated for movement at a common speed whereby saidpress elements can move along with each bag tube end, and tube endsupport means, such press elements being constructed and arranged forcoacting with such support means for pressing each end flap of eachspread bag tube end.

7. In an automatic bag bottom forming apparatus, the combinationcomprising: a bag tube conveyor including spaced gripping means forconsecutively gripping each of a plurality of bag tubes along theleading edge thereof and moving same in succession sideways thereofrelative to such apparatus in spaced relationship separated by aselected interval, mechanism for consequently spreading at least one endof such tubes moved by said conveyor and forming thereupon side and endflaps, such spreading and forming mechanism thereby forming a pair ofbag bottom side flaps and a pair of bag bottom end flaps and alsothereby forming diagonal fold lines upon each end flap, which fold linesare substantially equal in length, means for forming a pair of parallelbottom fold score lines on opposite sides of the center line of eachspread bag tube end,

each bottom fold score line terminating at the opposite extremitiesthereof along the respective opposite diagonal fold lines situated on acommon side of said center line, said parallel bottom fold score linesextending in the direction of motion of the bag tubes as moved by saidbag tube conveyor, the leading extremities of each such pair of saidbottom fold score lines as formed by said score line forming means beingpositioned along a line which is substantially perpendicular to the pathof movement of the bag tubes and which defines a bottom width line, thesame being true of the trailing extremities of each pair of such bottomfold score lines, such bottom width lines on a given tube end thusbeingsubstant-ially parallel, a plurality of pairs of end flap presselements, subsidiary conveyor means for moving such elements insuccession along the path of such tube ends as moved by said bag tubeconveyor, corresponding of such elements of any two succcssive pairsthereof being separated by the aforementioned selected interval which isthe same interval as that separating any two successive bag tubes movedby such bag tube conveyor, the press elements of each pair beingseparated by a distance substantially equal to the dimension between theaforementioned parallel bottom width lines which extend transversely ofthe leading and trailing end flaps of a given bag tube, such subsidiaryconveyor means and said bag tube conveyor means being operativelyassociated for movement at a common speed whereby each pair of presselements can move along with a given bag tube end, a support situatedadjacent said subsidiary conveyor means and such press elements forcoacting with such elements whereby the latter can press each end flapof each bag tube end as it moves adjacent thereto, each press elementhaving a pressing face which is conformed for pressing an end flap ofthe tube end in the region immediately adjacent opposite terminal pointsof the bottom width line of such end flap, and side flap folding meansfor acting upon such side flaps of a tube end during the aforementionedpressing action of such press elements for folding one side flap of thetube end over the other side flap thereby to bottom the tube end.

8. in an automatic bag bottom forming apparatus, a bag tube conveyorincluding spaced gripping means thereupon for consecutively gripping aplurality of bag tubes each on the leading edge thereof and pulling samein succession through said apparatus, said gripping means being spacedat a selected interval, mechanism for spreading a tube end of each ofthe tubes moved by said conveyor as the latter moves such bag tubesconsecutively therepast, such mechanism forming a leadin g and atrailing end flap upon at least one end of each of such bag tubes, aplurality of end flap press elements, supplementary conveyor means formounting said press elements in spaced relation thereupon and forconveying same in succssion in the same direction and at the same speedas said bag tube conveyor, such press elements being at least two innumber and positioned for acting upon the two end flaps of each spreadtube end, and means positioned along the path of said supplementaryconveyor means for folding portions of each such spread tube endcontemporaneous with the action of such press elements thereupon.

in an automatic bag bottom forming apparatus havin -"g tube conveyor forconveying a plurality of bag ti res in succession and in spaced relationrelative to said apparatus, and also having mechanism for spreading atleast one end of each bag tube as it is conveyed therepast, therebyforming thereupon two side flaps and two end flaps, ZUJQ also havingmeans for forming two bottom fold more lines upon each such spread tubeend, the combination therewith of means for applying a valve sleeve toan flap of each of said spread tube ends, a plurality of c d flap nrcsselements, supplementary conveyor means for mounting said press elementsin spaced relation thereupon, such press elements being at least two innumber and separated by an interval substantially equal to the 12 lengthof one of such bot-tom 'fold score lines, said supplementary conveyormeans being positioned for conveying such press elements in the samedirection as that of the aforementioned bag tube conveyor and along thepath of the spread bag tube ends, such press elements and supplementaryconveyor means being operatively associated with such bag tube conveyorfor acting upon each pair of end flaps of each spread bag tube end as itmoves along the path of such supplementary conveyor means, wherebyv eachof such elements presses against its respective end the region ofthettermini of such bottom fold score thereon, said sleeves so appliedto said end flaps being in position by the press elements pressingtherein an automatic bag bottom forming apparatus, the combinationcomprising a main bag tube conveyor; n ans for opening and spreading atleast one end of each tube conveyed by said conveyor, such opening andspreading means forming upon each such spread bag tube cud: two oppositeside flaps and two opposite end flaps, such opening and spreading meansthereby preliminarily forming the bag bottom and spreading the tube endwith respect to a center line parallel to the direction of motion of thebag tubes as moved by said main conveyor, at least a portion of each ofsaid end flaps being substantially triangular in configuration by virtueof diagonal fold lines formed thereupon in response to such bag tubespreading; means for forming a pair of parallel bottom fold score linesupon each such spread tube end on opposite sides of said center line andsubstantially parallel thereto, each bottom fold score line terminatingat the opposite extremities thereof along the respective oppositediagonal fold lines situated on the same side of said center line, saidparallel bottom fold score lines extending in the direction of motion ofthe bag tubes as moved by said main bag tube conveyor, the leadingextremities of each pair of such bottom fold score lines beingpositioned along a line which is substantially perpendicular to the pathof movement of the bag tubes and which defines therebetween the limits abottom Width line, the same being true of the trailing extremities ofsuch bag fold score lines, such bottom width lines thus beingsubstantially parallel; a plurality of end flap press elements;subsidiary conveyor means for mounting said elements in spaced relationthereon and for moving same in succession along the path of movement ofsuch spread tube ends, such press elements being at least two in number,the elements of each pair thereof for acting upon a given spread tubeend being separated by a distance substantially equal to the dimensionbetween the afore mentioned parallel bottom width lines of such tubeend; means for operative ly associating said subsidiary conveyor meansand said main bag tube conveyor for movement at a common speed, eachpair of said press elements moving along with a spread tube end; suchsubsidiary conveyor means comprising a first pair of endless bandssituated in parallel spaced relationshipside-by-s-ide and along the pathof the spread tube ends, there being a first group of such presselements secured to said first-named pair of endless bands for movementthereby, opposite extremities of each of such first group of presselements being secured to cor responding opposite locations of saidfirst pair of endless bands, said subsidiary conveyor means alsoincluding a second pair of endless bands also situated in parallelspaced relation side-by-side but interposed between the aforementionedfirst pair of bands, there being a second group of such press elementssecured each at the opposite extremities thereof to correspondingopposite locations of said second pair of bands, the interval separatingthe press elements mounted upon the first pair of bands being equal tothe interval separating such elements mounted upon the second pair ofbands; supporting means for said first pair of bands; supporting meansfor said second pair of :bands; the aforementioned operative means foroperatively associating said main bag tube conveyor and subsidiaryconveyor means including means for disengaging one of said pairs ofendless bands therefrom where- 13 by the pair of bands so disengaged isshiftable thereby to adjust the interval between the press elementsmounted thereupon and the corresponding press elements mounted upon theother pair of bands; tube end support means, each pair of such presselements for acting upon a tube end including one element mounted uponthe first-mentioned pair of bands and the other element mounted upon theother pair of bands, such pair coacting with such support 14 means forpressing the two end flaps of each spread tube end at opposite terminalpoints of its respective bottom width line; and side flap fold meanspositioned for acting upon the side flaps of each tube end for foldingsame one over the other thereby forming such bag bottomcontemporaneously with such pressing by the press elements.

No references cited.

